Cane Creek 40 ZS49/28.6 EC49/40 Headset, Black40 Series Zero Stack headsets set the standard for performance, durability and value. Drawing from the premium 110 Series design, the 40 Series includes all the features necessary for a durable, lightweight, long lasting headset. Compatible with tapered 1 1 8" to 1 1 2" steerer tubes, or straight 1 1 8" steerers with a conversion crown race (sold separately) Sealed ZN40 cartridge bearings 6000 series alloy cups and materials Steel crown race with